Slack Water
Australia · Queensland

Great Barrier Reef

The largest reef system on earth, from easy day trips to remote liveaboard reefs.

At a glance

Best months
June to November
Water
22–30°CAbout 22°C in winter to 30°C in summer
Visibility
15–30 m
Current
MildMostly mild on day-trip reefs
Certification
Open WaterMinimum Open Water
How you dive
Land-based or liveaboard

When to go

June to November; November to May is stinger season.

Overview

The Great Barrier Reef stretches for more than 2,000 km along the coast of Queensland. Most divers start from Cairns or Port Douglas and visit outer reefs on day boats, while liveaboards reach the remote northern reefs and the Coral Sea.

Day-trip reefs are well suited to new divers: calm, shallow and well organised. The further you travel, the better the reef condition and the bigger the animals tend to be.

The Australian winter, June to November, brings the clearest water and no dangerous jellyfish. From November to May, box and Irukandji jellyfish are present and stinger suits are needed. January to March is the wet season, with cyclone risk and rough crossings.

Who it suits

Open Water friendly. Remote northern reefs on liveaboards suit more experienced divers.

What you'll see

Vast hard coral reefsManta rays (more in winter)Minke whales (June and July, northern reefs)Coral spawning (October or November)

Know the risks

  • Box and Irukandji jellyfish November to May; wear a stinger suit
  • Cyclones and rough crossings January to March

Sources

Last reviewed 2026-10. Where sources disagree we use the more conservative range.